Treatment of hydrocarbon oil



March 26, 1940. c wl WATSON TREATMENT OF HYDROCARBON OIL Filed Nov. 6, 195'? QWN www.

ATTORNEY 'PatentedlML 26, 1940 Y ,UNIT ED TREATMENT or Hbtoeergoi@ I claude W; watson, Dobbsfrfr'y, Yr; assigner,"

. by mesnefassignments, to j'lexacogDevelopmenti l Corporation, New York,N. vY., va corporation' of Delaware Application November ylglll'gsuerial 'Nol' 17?0762 1.6 dem# (Giger-Qi This invention relates Ato improvements in methods of y convertinghig'h boiling hydrocarbons into low boiling hydrocarbons; l .According to myinvention a crude ovilf,ftopped crude oil or other heavy oilis distilled'toijemo've K -lowerboiling constituents'therefrom and to sep'- arate `desirable `fractions' therefromy comprising preferably a heavy reflux cond'ensate such as heavy gas oil, alight refluxcondensate -suchs as l0., light gas oil, a heavy gasoline or naphtha'.frac

tion and a light distillate'containing ga'solvine'nstituents. v

`The crude residue resulting from Athis distil1a Y. y A n y Y I mentinedor they maybe Yseparately introduced tion is'subjected to cracking to produce "addi-pI v` tionalk quantities of intermediate constituents which may be further cracked `to'produoe gasoline'. treatment may bemixedwith the`cracked'prod ucts resulting from cracking andfreforming'the heavy naphtha fraction and the combined stream .passed to a separatingzzone .wherein` vapors are separated from liquid. i residue.' L r`The` .vaporsfare Ifractionated and separatedxinto aheavy reux' (condensate, a light reux condensate,4 al-heavy` 5 naphtha fraction and a light distillate'product. f1

The heavy reux condensate lfast mentioned is preferably mixed with the heavyreflux-condensate fraction separated from the `feedstock and the combined stream iszsubjected tcv a separate cracking treatment to 'produceadditionalfquantities of intermediate constituents'which' ar'efsuitable .for further conversionunder drastic-'conditions into gasoline. The cracked products from V any suitable manner as byl being brought into indirect heat'exchange ywith hot products obtained v35 .l dur-ingthe subsequent cracking operations of the this separate crackingY treatment are introduced into the separating zonet-above mentioned and vapors are separated from liquid `residuealong with the productsfrom' vthe crackingzone firstk mentioned. f. p

The `light reflux condensate vseparated 'from f 4o the products fromjthecracking `zone rst men# tioned is preferably mixed 4with ythe light Areflux condensate fraction separated from the jfeed stock and the combined stream is passed through a separate cracking zone wherein the oil is main'- tainedunder high temperature. and "high pressure conditions tor eiect the desired extent `of cracking thereof. The cracked products -are passed to a separate evaporator to separatevvapors from liquid residue.A The vapors are fractionated toseparate condensate oil containing insufficiently crackedproductsv from afinal distilfl late product having the desired boilingrange.

The condensate oil last mentioned is recycled through the high temperature and highA pressure cracking zone for further cracking treatment ffabove'fdescribd;

tion v separated fromv vthev f'product's leaving theA finto this separating )zn'eiu A u 4 n Having described the general nature' andobj'ect The cracked .products from the crackingl K.0f-my, inventn, I WllfIlOW give, a detailed dejiqnfgfwiththe light? condensates'derived-.irgm

the fpro'du'cts from`rv theotherfc'racki,ngI treatments Q Theheavylnaphtha fraction separatedfromthe -feedstock'tcii'geth'er with the Aheavy naphtha fraf'.

cracking 'zones 'above described vis preferably passed gtlifrough a? 'reforlmi,ng` 'and cracking y*Zone to' imlprove` the-janti-,knoc'k quality thereof .and `.the

" products from thezreforming and crackingzonego fare preferably mixedwrith the products Vfrornfthe f' other Ecracking zonesabove describedprior' to theirf introduction "intothev separatingv zonevv first Vscription thereof in which reference Will be madel :'iReferring now-to the drawing, the reference cha'ra'ct'erjIll designatesv afpump which forces fresh charging oil such asy crude oil,l topped crude "oilcr otherV heavy 'oil through aline "I2 into-"the 'bottomfportion' I3 Aof a 'crude stripping or' fractionating' tower' AIII wherein'.y the charging-oil'is 'subjected Vto distillation `,and liberated yvapors 'are fractionated in passing upwardly inthe tower 4 III. The stripper or fractionatingtowergl4 may` @13.0 v

be maintained under atmospheric orsuperatmos- 'pheric pressure. The fresh charging''oil is lpreflerably preheated to" a ydistillingtemperature in `process or by being heated in a preheating coil.

The' stripping or fractionating tower I4 is providedwith trapout tray IIv having .a hoodI'8,

trapouttray 22having1a hood 24, an'd altrapouf :4o .v

Itray Zhaving a hood 28.Vl The ptrapout trays l' are verticallyspaced withinl the stripper'or frac'.- tionating tower I4 so that several fractionsmay be collected and withdrawn from the tower;y I4

.` during ldistillation and fractionationoffthe in ,-2.215 y y ltroduced heavyoih.` i y y g .V' During distillation'` and fractionationl offthe .heavy oilin` thegstripper or fractionating towen y y AII4, it is separated into fractions and aliquidresil due. .A heavy reflux condensatesuch as a `heavy 50 mixed with kthe :lighty reux condensatepwhich is withdrawn from the bottom-of the fractionating ,l

tower 90 and passed through line A|34 and prei-y erably admixedv with the l.light reux condensate which is .withdrawn from tapout tray 22 in tower |.4 and-passed through vline.|42. t The combined stream'offcondensate kcil and light refluxl condensates ispassed through.v the cracking zone or coil |38 as, before describedf` I The top portion of the'fractionatingittower` |58 may be provided with a coil |04 to provide cooling for the top of the tower. The vapors remaining Q after fractionation in the fractionating rtower |58 leave thetop ofthe tower throughline'l and are passed through condensed |08 tc form a distillate which is collected 'in receiver Ilii'having a Valved gas outlet |12 and-.a valved liquid outlet I |14. A portion of the'l distillate'may be passed through line'l'l 'by pump llxandreturned to the top portion of the fractionating tower |58 asreux v' l lA typical operation contemplated by my' invention will now be given but it is to be understood thatI am not to'berestrictedzthereto;. The fresh charging `oil suchv as a crude oil yis preheated yto aldistilling temperature of about.600-

800 F; vin -any suitablemanner and is `introduced l into the' crude stripper or fractionating Ytower M maintained under a pressure from' atmospheric pressure to about 100 pounds :per `square inch.

' During distillation vand 'fractionation thev heavy [charging oil is separated into fractions and a liquid'residue. The yliquid residue has. an initial boilingpoint of about G50-750 F. vThe separated fractionsk comprise a heavy reuxcondensate such as a heavy gas oil consisting essentially of constituents boiling vabove 650-750F. collected onA `trapout trayV I8, .a light reux ycondensate such as a light gas oil having an endpoint of about S-'750 F. which is-collectedon trapout y tray 22 and a heavy naphtha fraction having 'an initial boiling point ofabout Z50-350911'. and

lected on trapout tray 26. 'A' light 'distillate product is collected in receiver 34. y g

The liquid 'residuefrom the bottom of thecrude stripper orfractionating tower'lll. ispassed through they once-through viscosity'`V breaking zone or coil' 50 wherein it is maintained under,-A a pressure of. vabout '75 to liOOpounds per square.,l inch` andv at a temperature vof "about'8`50950 F. preferably with such 'time ofreaction that the cracking isk the maximum allowable' vconsistent with the length of run dueto coke forma`` tion. By operating in this way to obtainfthe rmaximum amount kof 'conversion in the viscosityv breaking zone 50, a maximumoverall yield'r of The heavyrelux condensate which is collected on trapout4 tray v(i8 :in the combined evaporator andfractionating tower consistsessentially of constituents 'boiling abo-ve G50-750 F. and thisA heavy reflux condensate is combined With/ the heavy reflux condensate which"y collects :on trap- .y

out tray I6 `in the crude stripper or fractionating tower 4. rThe combined streamis passed through the `recycling viscosity breaking Zone or coil 18 wherein the'oil is maintained under ka pressure of about to 1000 pounds per square 1 inch and a temperature of aboutr900'toA 1000 to effect further conversion of heavy constituents of the oil into a'relatively largefamountf of jinterf mediate constituents suitable for `further crackling under more drasticzconditions in crackingl zone or coil-|38.` y'The treated heavy reux con' densates leave therecycling viscosity breaking 4zone orcoil y|37 ata temperature,1"for example,

of about I950 F. and under pressure of'about 400 Apoundsper square inch. f

'I'he heavy naphtha fraction which collects on trapout tray 94 inzthe fractionatingtower 90 has an end point of about 550 to 650 F..'.and contains gasoline constituents separatedlfrom vapors f derivedlfrcm' the cracking zones y50and 13. This heavy naphtha fraction isi preferably mixed with the heavy naphtha fraction withdrawn from the trapout 'tray'i` in the l crude stripper or fractionating 1 tower Hl and thel combined stream passed?v through the-.reformi ng or cracking zone y or'coill I 04. In the reforming or cracking zone or `coil |04 the stream of heavy naphthafractions `is subjected itoa"pressur e;of 'about 500 to 1000 .pounds perv square inch-and is maintained at a temperature'of about y950'to 1150" F. to effectthe desiredv conversion ofA the,r gasoline l constituents thereof. v*':The 'treated Nnaphthaif'ractio'n leaves the cracking zone or coil |04 vat a temperature,

for example, of about 1050PF.' and'under pressure` oi" about 750 pounds Iper square inch.

The streams.y of products vleaving the oncethrough viscosity breaking zoneo'r-'coil `5|), the

recycling viscosity` breaking-zone orcoil 18 and l `the reforming or -cracking zone or coil |04 areI preferably combinedv and. introduced, into the evaporator or separating zone l58'of the com-` bined evaporator; and .fractionating tower |30 'wherein a separation into vapors and liquid-residue occurs. v",Ihe highly 'heated productsk from the 'cracking l andreforming rzone' |04 assist inv vaporizing light` constituentsvr rom 'the rviscosity zones 50 and 18.

broken products Afrom the viscosity breaking '.Thelight reilux condensate collected at the bottomofthe fractionating tower has an end point of'abou't 650 to'750 F.'and is admixed with the light reflux condensate oilcollected on' trapout tray 22 "in the crude vstripperorl fracj tionating towerfM and with thel condensate oil withdrawn from .the bottom of the fractionating towerll. -The .combined stream is' passed 'throughthejcracking zoneor Acoil: |30 lwherein the oilis' maintained'` under a pressurev ofaboutf -.200 to .1000` poundsV per square inch land ata temperature of about l900 to y105091, to eect the -desired cracking. of 'the oil." The products leave the cracking'zone or coil ,|38 at a' temperature, for example. of yaboutw990" F. `and under a. pressure' of abouteOQ-pounds per square inch' I and are separated into vapo-rs and liquid residue."

The vapcrs'arefractionated to separate the conn densate oil abovede'soribed from a distillate such as gasoline having the' desired boiling range.

The distillate iscollected in receiver |10 vand y may be further treated, as desir-ed;` y I The'light'distillates collected in receivers 34 and l 20 may be combined with the naphtha fractionsand subjected to vreforming'and' cracking l.in-"title -reiormingfzone |041or 'may' be' otherwise treated as desired. t

While I `have described a particular embodistood that my invention is not restricted thereto, and that various modifications and adaptations `thereof may be made Without departing from the spirit of the invention.

70 ment of my invention, it isto be expressly undery rate a liquid residue fromi'a `heavy gas oil condensate anda light gas oil condensate, passingY the liquid residue through a viscosity `breaking zone wherein the residue is subjected to cracking to effect conversion into lower boiling constituents includingxa relatively largeryield'of intermediate constituents, passing the products from the viscosity breaking zone to a separating Zone to-separatevapors from a liquid residue, fractionating the separatedvapors to separate a second heavy gas 'oil condensate from a second light gas oil condensatecomprisi'ng intermediate constituents formed in they viscosity-breaking operations ofthe process, combining the first and second heavy gas oil condensates and passing them througha second viscosity breaking zone wherein the condensates are subjected to cracking to effect conversion into a relatively large yield of intermediate constituents, passing the products from said second viscosityV breaking zone into'said separating zone to separate vapors from a liquid residue, combining the rst and second light gas oil condensates and passing J them through cracking zone wherein the condensates are maintained under high temperature and superatmospheric pressure conditions to effect vthe desiredconversion, passing the products from said cracking zone to a second separating zone to separate vapors from a liquid residue and iractionating the last mentioned vapors to separate a distillate having the desired boiling range from condensateoil; v f

2. A process as defined in claim l wherein the condensate o-il is combined with the light reflux condensates andthe combined stream passed through said cracking zone to effect cracking thereof.

A process for converting higher boiling hydrocarbons into lower boiling hydrocarbons which comprises subjecting crude petroleum vcharging stock to fractionaldistillation to separate a liquid residue from a heavy gas oil condensate, a light gas oil condensate and a naphtha fraction, passing the liquid residue through a viscosity break- 1 ing zone wherein the liquid residue is subjected to cracking to` effect conversion thereof into lower boiling constituents including a relatively large yield of intermediate constituents, passingk thel i intermediate constituents formed in the viscositybreaking operations of the process from a second naphtha fraction, combining the rst `and second heavy gas oil condensates and-passing them through a second viscosity breaking Zone wherein the condensates are subjected to crack-` ing to eifect conversion thereof into Aa relatively large yield of intermediate constituents, passing' the products from said second viscosity breaking zone into said separating zone toeiect separation of vaporsr from :a liquid residue, combining.v the naphtha fractions `and passing them through a cracking zone maintained under `high temperature and high pressure conditions vto effect the desired extent ofcracking and reforming, passing the productsfrom the cracking zone into said separating zone to separate vapors from liquid residue, combining the first and second light gas oil condensates and passing-them through a sec- -ond cracking zone wherein the condensates are maintained under high temperature andl superatmospheric pressure conditions to effect the desired conversion thereof, passing the products from said second cracking zone to a second separating Zone to separate vapors from l'a liquid residue and fractionatingthe last mentioned vapors to separate-a distillate having the desired boiling range from condensate oil. 'i

, 4. A process as deflnedin claim 3 wherein the condensate oil is combined with the light .reflux condensates and the combined stream passed throughV ysaid second'r cracking zone' to effect cracking thereof. a

5. Aprocess for converting higher boiling hydrocarbons into lower boiling Yhydrocarbons which' comprises subjecting crude petroleum Vcharging;"stock to fractional distillation to separate a yliquid residue from a heavy gas oil con-` densate and a light gasoil condensate, passing the liquid. residue through a single-pass viscosity breaking Zone wherein the liquidy residueis subjected tocracking toeIect conversionjthereof into lower boiling hydrocarbons includinga relatively high `yield of intermediate constituents,

passingthe products from the viscositybreaking zone to a separatingzone to separate vapors from a liquid residue,v fractionating the vapors to separateV asecond heavy gas-oil condensateV yfrom a second'light gas oil condensate comprising intermediate constituents formed in the viscositybreaking. operations of the process,` recycling the second heavy gas oil condensate together withthe iirstheavy gas oil` condensate: through a'y second Yviscosity breakingzone wherein the condensates are subjectedto cracking to' effect conversion thereof into a relatively high yield of lower boiling constituents including a large proportion of intermediate constituents, passing .the products from the recycling viscosity `breaking zone into said separating zone-to separate vapors from a liquid residue, combining the first andesecond light gas oil `condensatesand passinguthem through a cracking Zone wherein Vthe condensates are maintained under high' `temperature andhigh pressure `conditions to effect the desired conversion thereof, passing the products from saidl cracking zone to a secondseparating zoneVv to separate vapors from a liquid residue and fractionating the last mentioned vapors to separate a distillate havingthe 'desired boiling range fromcondensate oil. l I

6. A process as defined `in claim 5 wherein the y condensate Gillis-combined with'the lightreflux condensates and the combined stream passed through said vcracking zone to effect cracking thereof.

CLAUDE W. WATSON. 

